UDC 621.921.34-413:662.23.05
A. A. Shulzhenko, V. G. Gargin, N. A. Rusinova, A. S. Osipov, M. G. Loshak, L. I. Aleksandrova, R. K. Bogdanov, A. P. Zakora, V. N. Tkach (Kiev)
Diamond polycrystalline composite material and its properties
The results of experimental studies on the creation of a diamond polycrystalline material for equipping drill bits are presented. The angles of wetting of graphite by sintering process-activating additives Ni, Co and their alloy are determined. Material tests have shown that among the studied composites, the composite of the Salm-Co-34Ni composition has the greatest durability and the highest values of tensile strength.
Key words: diamond, composite, properties, pressure, temperature, nickel, cobalt, cobalt-nickel alloy.
UDC 536.631:621.921.34
O. O. Vasilyev, V. B. Muratov, T. I. Duda (m. Kiev)
Investigation of low-temperature heat capacity of diamond: development and experiment
The thermal capacity of diamond was analyzed on the basis of reliable data on spectroscopic and spring-dynamic characteristics and experimental investigation of the low-temperature (50-300 K) heat capacity of synthetic diamond from the General Electrics company. Based on the derivation of temperature deposits and heat capacity, the significance of the basic thermodynamic functions of diamond for standard minds has been determined. The results are tabulated and recommended for practical use.
Key words: diamond, specific heat, phonon spectrum, adiabatic calorimetry, enthalpy.
UDC 620.22.66.067.124
P. S. Kisly (Kyiv) E. S. Gevorkyan, V. A. Shkuropatenko, Yu. G. Gutsalenko (Kharkov)
Preparation of materials from aluminum oxide nanopowders using modern consolidation methods
The processes of hot pressing of aluminum oxide nanopowders have been studied. The features of their compaction during hot pressing, as well as the effect of hot pressing modes on the structure of materials from nano- and submicron aluminum oxide powders are considered. The kinetics of grain growth of nano- and submicron powders during hot pressing, the dependence of the density of the obtained materials on the hot pressing modes are studied.
Keywords: nanopowders, aluminum oxide, consolidation method, hot pressing, material structure, density, grain growth kinetics.
UDC 669.018.25
A. F. Lisovsky (Kyiv, Ukraine)
On the creation of nanostructured hard alloys WC-Co
The size range of existence of WC nanoparticles and nanostructured hard alloys WC-Co is substantiated. It is shown that existing sintering technologies do not allow obtaining pore-free WC-Co hard alloys with a carbide particle size of 5-40 nm. A method for forming nanostructured hard alloys is proposed.
Keywords: sintered hard alloys, nanostructure, technology.
UDC 666.11.01:621.921-419
S.A. Kukharenko, A.E. Shilo, P.P. Itsenko, A.N. Kutsay (Kiev)
The influence of titanium dioxide on the structure of silicate multicomponent glasses
The main results of the study of the interaction of glass melts with refractory titanium dioxide are presented and summarized. It is shown that titanium dioxide partially dissolves in sodium borosilicate glass. By integrating into the structural network of glass, the titanium cation isomorphically replaces silicon and forms a single strong titanium-boron-silicon-oxygen framework in the glass, which allows increasing the wear and heat resistance of the composition.
Keywords: multicomponent silicate systems, titanium dioxide, interaction, dissolution, silicon-oxygen framework of glass, quantitative phase analysis, abrasive-containing glass composites.
UDC 539.53:549.517.1
S. N. Dub (Kiev) V. V. Brazhkin (Troitsk, Russia) N. V. Novikov (Kiev) G. N. Tolmacheva (Kharkiv) P. M. Litvin (Kiev) L. M. Lityagina, T. I. Dyuzheva (Troitsk, Russia)
Comparative studies of mechanical properties of stishovite and sapphire single crystals by nanoindentation
The results of comparative tests of stishovite and sapphire single crystals by nanoindentation are presented. It was found that the nanohardness of the (0001) plane of sapphire at an indentation depth of 200 nm is 29.1±0.1 GPa, while the nanohardness of the (110) plane of stishovite under the same test conditions is 38.1±0.6 GPa. The specifics of the elastic-plastic transition in sapphire and stishovite single crystals, as well as in polycrystalline ceramics based on aluminum oxide, with deformation localized in the submicron region were studied. An anomalous character of the elastic-plastic transition in the stishovite single crystal was discovered. The possibility is discussed that the anomalous mechanical behavior of stishovite at the nanoscale can be caused by strong softening of the lattice as a precursor to the formation of a poststishovite phase of silica with the CaCl2 structure under high pressure in the indentation.
Keywords: nanoindentation, nanohardness, elastic-plastic transition, sapphire, stishovite.
UDC 621.623
Yu. D. Filatov, A. Yu. Filatov, O. O. Sirota, V. P. Yashchuk (Kiev) G. Monteil (Besancon, France) W. Heisel, M. Storchak (Stuttgart, Germany) i)
The Effect of Scattering of Tool Wear Particles in the Contact Zone on the Formation of the Machined Surface Microprofile during Quartz Polishing
The interaction and scattering of wear particles in the contact zone of the tool and the workpiece during polishing is described, and the oscillatory structure of scattering of tool wear particles on sludge particles and on wear particles is explained. It is shown that the differential cross-section of scattering of wear particles on sludge particles, as well as on wear particles, is maximum when scattering forward in the central sections of the contact zone. The coordinate dependence of the differential cross-section of scattering of tool wear particles and the dependence of the height of the microprofile of the machined surface of the workpiece on the radius of the circular zones are calculated. The correspondence of the experimental and theoretical curves of the microroughness of the profile of the polished surface of the quartz workpiece is shown.
Keywords: polishing, particle scattering, scattering cross-section, microprofile.
UDC 621.762:620.22-419:669.25
A. A. Zaitsev, D. A. Sidorenko, E. A. Levashov, V. V. Kurbatkina, V. A. Andreev, S. I. Rupasov, P. V. Sevastyanov (Moscow)
Diamond tool for cutting highly reinforced concrete with a metal binder dispersion-strengthened by nanoparticles
Two binders dispersion-strengthened by WC and ZrO2 nanoparticles, used in the production of diamond tools for cutting reinforced concrete, are described. The nature of the distribution of nanoparticles in the metal matrix is studied, the physicomechanical and tribological properties of the binders are determined. It is shown that the use of dispersion-strengthened binders leads to an increase in the tool life up to 60 ‰ without reducing the cutting speed.
Keywords: diamond tool bonds, dispersion-hardened materials, diamond cutting segment wheel, cutting of reinforced concrete.
UDC 621.921.34-492.2:620.22-419
A. A. Bochechka, S. N. Nazarchuk, G. S. Oleynik (Kyiv)
To obtain self-bonded diamond
The possibility of forming self-bonded diamond material by sintering at high pressure of diamond micropowders of static synthesis and diamond nanopowders of detonation synthesis is shown.
Keywords: self-bonded diamond material, sintering, micropowders, nanopowders, static synthesis, detonation synthesis.